Tamron 28 to 300mm Lens
How Compact Can You Get

sorcadmin's picture

One of the real fun things you can do with a long tele lens is compress space, an effect known as "stacking." Here's a photo of a marketplace in Seoul made with the 28mm setting (A, above), then with the lens racked out to the full 300mm (B, below). Note how the signs turn into a visual collage, an effect of the focal length crop. Also note how sharply the lettering reads.
Photos © 2002, George Schaub, All Rights Reserved

If you go way back you remember the first telephoto zoom lenses as heavy, ungainly things that were often more trouble than they were worth. Travel a bit ahead in time and check out the wide-to-tele zooms, and you get the same thing, with all sorts of problems that were not quite solved at numerous focal length settings. In the here and now all that has changed, especially when you consider the latest XR series lens from Tamron--the 28-300mm f/3.5-6.3. When we spell out the specs you might not believe them. The lens is 3.3" in length and weighs 13.5 oz and has a filter diameter of 62mm. The minimum focusing distance is 19.29, throughout the entire focal length range.

Gotten off the floor yet? Here's a lens that covers just about every focal length setting except super wide that might just be the be-all and end-all for travel photographers. Indeed, Tamron claims that this is the world's lightest, most compact 28-300mm yet, and who are we to doubt them? All we can do is be impressed with what they've accomplished with this lens. We couldn't wait to get in the field to see if all this impressive technology can take a good picture as well. Indeed, when we first opened the box we were sure it was the wrong lens and the box itself was mislabeled. But lo and behold it was the one!

But before we venture forth, we thought we'd take a few moments to run you through the alphabet soup technology that makes this lens what it is, including XR, ASL, LD, AD, ADAH, ZL, BBAR, and IF. Confused yet? Well, for those who might want to delve into these mysterious acronyms and abbreviations, see the accompanying sidebar below.

Another tidbit of advanced tech shown in this lens is what Tamron dubs a "Super Hybrid Mount." The bayonet mount on the lens uses hybrid materials made of stainless steel and what they call "engineering plastic." The benefit is a reduction in weight and strength that they claim is equal to that of metallic (brass) material normally used for the mount. This heavy-duty mount is designed to extend the flange portion of the mount, an important connecting point between camera and lens. On the weight side, the mount is 70 percent lighter when compared to the previous Tamron 28-300mm zoom.

B

In The Field
All this tech stuff is most impressive, but the picture tells the tale. As mentioned, the lens is about as long and heavy as a modern 35-105mm. I used it on a Canon EOS-1N and every mode worked great and autofocusing was silent and efficient. For the most part I worked in AV mode, and shot with Agfa's new ISO 400 Optima color print film. This gave me a good hand holdable shutter speed in most instances, especially since I try to get it at f/8 for most images. At the wider settings the lens is crisp and clear with no noticeable falloff at all. At the tele settings, particularly 300mm, edge sharpness was also very good, although keeping the shutter speed at or over 1/250 sec is always recommended for this focal length.

In all, the Tamron 28-300mm lens is perhaps the perfect traveling companion. It handles just about every location and point of view, and does so with a quality that is pleasing to the eye. It's almost hard to believe that a zoom of this magnitude and range can deliver the goods, but this Tamron will now be a constant companion on my travels. All I need to do is add a fast 24mm for available light, and I'm all set for the road.

For more information, contact Tamron at www.tamron.com.

Even when you're not using the lens throughout its range it delivers sharp and clear images at more "normal" settings, here at 75mm.

The Alphabet Soup Of Tamron Lens Technology

XR: The namesake of the lens line stands for Extra Refractive Index, which is a numerical expression that compares the speed of light in a transparent medium, such as glass, with the speed of light in the air. The higher the number the thinner a given element. Extra Refractive Index glass is said to bend light more effectively than normal or lower refractive index glass and can compensate for specific aberrations within an optical design.


A

B

C

D

Made through a hotel window looking at downtown Seoul, Korea, this
series of prints shows the lens set at 28mm (A), about 125mm (B), 220mm (C), and full out at 300mm (D). It's hard to believe you can get such crisp image quality from a lens this small with such a wide focal length range.

Benefits: Shortens length of the entire optical system; shorter distance from the diaphragm to the front surface of the objective lens; lessens diameter of the front element; smaller overall lens diameter; smaller lens and minimal aberration.

ASL: This stands for aspherical elements, and Tamron has developed a process that has allowed for the mass production of aspherics they call Hybrid Aspherical.

Benefits: One aspheric can replace two regular elements without sacrificing optical performance; improvement of corner-to-corner sharpness; reduction of distortion at wide angle focal lengths; and provides even illumination while it reduces flare.

LD & AD: Low Dispersion (LD) elements are made from special glass with extremely low dispersion indices that separate or refract a ray of light into rainbow colors. Chromatic aberration is a form of optical noise that reduces sharpness and can plague telephoto and zoom telephoto lenses. AD (Anomalous Dispersion) glass is a special optical glass that delivers an abnormally large partial dispersion ratio, the amount of dispersion at a given wavelength range within visible light.

Benefits: The LD and AD elements are said to effectively compensate for chromatic aberration and improve contrast and sharpness. Solves both chromatic aberrations in telephoto lenses and lateral chromatic aberrations associated with wide angle lenses.

ADAH: This stands for "Anomalous Dispersion-Hybrid Aspherical," the manufacturing method of adhering a specially treated aspherical layer to the finished AD glass element.

Benefits: Perfect bonding of the two elements while maintaining compact size and lightweight.

ZL: The Zoom Lock can be activated when the lens is at the 28mm focal length setting.

Benefits: Prevents the dreaded "zoom creep"; the lens will not slip out to the longer settings when you are carrying it around.

BBAR: A thin dielectric or metallic film applied to the lens.
Benefits: Reduces reflections and increases the effective transmission of the element.

IF: Internal Focusing enables focusing of the lens without changing its length. All internal optical movement is limited to the interior of the non-extending lens barrel.

Benefits: Compact, lightweight construction; closer focusing distances.

Share | |